1. Field of the Invention
The present invention generally relates to switches. More particular, the present invention relates to switches that can be operated without physically contacting the switch but rather by attenuating the audio input signal of a microphone. Even more particularly, the present invention relates to an acoustic switch apparatus incorporated into a hearing aid and activated by attenuating the audio input signal that allows the user to control the selection of parameter sets within the hearing aid.
2. The Background Art
In any given day, one may expect to be exposed to a wide variety of radically different sound environments. Therefore, it would be desirable to have a hearing aid which is capable of adequately responding to these diverse sound environments by allowing the user the choice of selecting from among a plurality of parameter sets (e.g., volume control, frequency response functions, mute, etc.) to optimize performance. A user wearing such a device would be able to select the most suitable parameter set to fit individual comfort needs to accommodate a particular sound environment that the user may encounter.
The ability to construct a miniaturized hearing aid with the capability of switching to a plurality of parameter sets has existed for some time. Unfortunately, by solving the problem of placing a large variety of features into a miniaturized hearing aid, a new problem has arisen. That is, where can the manufacturer place the switches needed to control these new features. By miniaturizing the device to approximately the size of a conventional pea, the physical limitations of where to place a switch have become a serious concern. This problem of where to place the mechanical component of the switch that controls a miniaturized hearing aid is even more aggravated when the device is worn deep within the user""s ear canal.
For custom hearing aids, the typical solution has been to provide an electro-mechanical switch on the faceplate, such as a push button or a toggle switch. These electro-mechanical switches physically consume faceplate area and volume behind the faceplate. For very small devices that are to be worn deep within the ear canal, it is often impossible to provide a switch because there is simply no space available on the faceplate.
Wireless remote control systems offer the advantage of eliminating the need for any additional switch component on the faceplate. However, remote control actuator hearing aid systems carry with them a number of inherent undesirable features. Remote actuators often have complicated control systems that can make them difficult to operate by the average hearing aid user. This problem may be further aggravated by the user having limited manual dexterity due to some debilitating illness, such as arthritis. Furthermore, by their very nature, these remote control devices require at least two separate standalone components (i.e., the hearing aid component and the remote control component). Therefore, the user of a remote control hearing aid will be burdened by carrying the remote actuator at all times, if the user desires to control the switching operations of the remote controlled hearing aid.
Capacitive-contact switches have been used as switching devices because these components require a minimum area on the faceplate. However, these devices do require some faceplate area. Furthermore, these devices require the user to physically touch the switch in order to control the switch, which may become burdensome when the user""s dexterity is limited by some debilitating illness, such as arthritis.
Another approach to solving this problem has been to install switches as integrated components within the battery door assemblies. These devices are advantageous in that there is no need for a switch on the faceplate. However, these devices suffer a number of limitations in that they are generally constructed as larger units and are often more expensive.
Therefore, there is a need for a switch apparatus that can be controlled by a user without a need to physically touch the switch apparatus.
The present invention provides a switch method and apparatus that is switchable among a plurality of operational modes by attenuating an input audio signal detected by the apparatus. The apparatus includes a microphone which converts the input audio signal to an input electrical signal (IES), a first memory which stores a threshold value, a second memory which stores at least one parameter set, a selector which is responsive to the first memory and to the IES for selecting a first parameter set as an enabled parameter set, and a signal conditioner coupled to the IES, the signal conditioner being responsive to the IES and to an enabled parameter set for producing a conditioned electrical signal (CES). An alternative switch method and apparatus switchable among a plurality of operational modes by attenuating an input audio signal detected by the apparatus includes a microphone which converts the input audio signal to an IES, a signal envelope detector (SED) coupled to the IES, the SED having a first time constant, wherein the SED produces a SED output in response to the IES, a noise envelope detector (NED) coupled to the IES, the NED having a second time constant that is greater than the first time constant, the NED produces a NED output in response to the IES, a first memory which stores at least one parameter set, a selector which is responsive to the SED output and to the NED output for selecting a first parameter set as an enabled parameter set, and a signal conditioner coupled to the IES, the signal conditioner being responsive to the IES and to an enabled parameter set for producing a CES.